Unable to find commercial.key

I am just recovering back from failure and got a certificate from GoDaddy. However per wiki it says I need to have a commercial.key. now would like to know how i can get the commercial.key or how do I generate it since the default installation doesn't show up the key.

I am just recovering back from failure and got a certificate from GoDaddy. However per wiki it says I need to have a commercial.key. now would like to know how i can get the commercial.key or how do I generate it since the default installation doesn't show up the key.